Runoff represents the water flow that occurs when soil is saturated and excess water flows across a soil surface. While runoff is problematic owing to erosive loss of topsoil, the deleterious effects are compounded when fertilizer or active ingredients are transported along with runoff. Representative of these complications is damage to downstream waterways that include eutrophication, anaerobic dead zones, and bioaccumulation of active ingredients such as herbicides and insecticides.
As various soil types have widely varying capacity to hold water, the amount of runoff in general tends to vary proportionally with the water holding capacity of a given soil. As clay containing soil tends to be slow to absorb water, clay soils are particularly prone to runoff problems and the conveyance of human applied material into downstream bodies of water. Clay subsoil layers have slow water infiltration rates and as such show exceptionally high degrees of runoff in response to a heavy rain.
In response to problems associated with a spray application drift, there is an accelerating trend toward delivery of agents such as plant nutrients, fertilizers, pesticides to target cultivated vegetation through resort to broadcast application of pelletized products containing a given active ingredient. Representative of such methods of broadcast application is the use of a rotary spreader. Such pellets are well suited for application to agricultural fields, golf courses, parks, lawns, gardens, and woodlands. Such granular products typically have a size in the range of 0.5 mm to about 10 mm and can be based on various inert substances such as limestone, cellulosic particulates such as sawdust, corncob, stover, and wheat chaff. Representative of such materials are DG® and DG Lite® produced by The Andersons and based on dolomite or dolomite inclusive of wood flour with a binder holding together the constituent granules into agglomerated pellets, respectively. Unfortunately, when conventional pellets are applied to clay rich soils, the pellets upon wetting merely rest on the soil surface and the components of the pellets including active ingredients present in the delivered pellet exhibit a high degree of runoff causing downstream pollution and ineffective vegetation treatment.
Efforts to bind dispersed particles to soil have met with limited success and relied on synthetic polymers/ Exemplary of these efforts is U.S. Pat. No. 8,316,580 in which polyacrylamide particles are used to bind to soil. Unfortunately, acrylamide monomer present either through incomplete polymerization or polymer degradation is known to be a potent neurotoxin.
Thus, there exists a need for a soil adherent pellet and the ability to deliver active ingredients to such soil with such a pellet. There further exists a need to limit the amount of applied active agent runoff associated with pellet distribution to an area to limit runoff associated downstream conveyance of applied active agents.